In February, three U.S. Chemical Safety Board (CSB) investigators deployed to the Packaging Corporation of America (PCA) plant in DeRidder, La., where an explosion killed three workers on Feb. 8. Initial reports state that the explosion occurred while contractors were performing welding on a tank during a facility shutdown. According to CSB’s press release, the explosion was powerful enough to cause the tank to fly and land in a different area of the plant, which produces containerboard and corrugated packaging.

The agency has previously investigated several hot-work incidents across the U.S., including an explosion at a different PCA plant in Wisconsin that killed three workers in 2008. Following that explosion, CSB issued a safety bulletin about the hazards of conducting hot work in a variety of industries. The bulletin lists seven “key lessons” to help prevent worker deaths during hot work in and around storage tanks containing flammable materials. In 2010, the agency released a video called “Dangers of Hot Work” that focuses on preventing flammable vapor explosions caused by welding and cutting.